1. Field of the Invention
The present invention relates to a nailing machine.
2. Description of the Prior Art
A conventional nailing machine is operable to drive nails stored in a magazine one after another from a lower end of a driver guide by means of a driver driven by compressed air. The nails are stored in series within the magazine. A contact arm is provided for preventing an accidental driving of the nails when a nailing operation is not performed. Unless the contact arm is moved upwardly through abutment on a work, the driver may not be driven even if a trigger is turned on.
Such a conventional nailing machine is disclosed in Japanese Laid-Open Utility Model Publication No. 4-133580. The nailing machine of this publication is adapted to drive nails for finishing purposes and includes a driver guide and a plate-like contact arm which confronts the driver guide by a separation plane extending in a longitudinal direction of the driver guide. The driver guide and the contact arm cooperate to form a nail driving passage therebetween. The driver guide extends downwardly from a body of the nailing machine. The contact arm is vertically slidable relative to the driver guide and is biased downwardly by a spring. The contact arm is normally held in a position where a lower end of the contact arm extends downwardly from the driver guide by a predetermined distance.
With the nailing machine of Japanese Laid-Open Utility Model Publication No. 4-133580, when a trigger is pulled or turned on, the nails are ejected from a lower end of the driver guide through the nail driving passage and are then driven into a work, on the condition that the contact arm is pressed on the work and is moved upwardly relative to the driver guide by a predetermined distance. The driving depth of the nails can be adjusted by varying an upper stroke end of the contact arm.
Thus, with the nailing machine of this publication, since the nail driving passage is formed between the fixed driver guide and the contact arm which is movable vertically relative to the driver guide, the lower end of the contact arm may be positioned downwardly of the lower end of the driver guide, depending on the determined driving depth, even if the contact arm has been moved to its upper stroke end. In this case, the nails are not guided between the lower ends of the driver guide and the contact arm. This means that the nails are not guided just before they are driven into the work, so that the driving distance of the nails becomes unstable and the nails cannot be driven into the work at aimed positions.